Modification of Ag-doped BaTiO_3 powders through La gaseous penetration route  

作　　者：李佳龙 郝素娥 付东升 王威 马天龙 王春艳 

机构地区：[1]Department of Chemistry,Harbin Institute of Technology

出　　处：《Journal of Rare Earths》2010年第S1期154-157,共4页稀土学报（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (20571020)

摘　　要：The Ag-doped BaTiO3(BATO) polycrystalline powders were fabricated by Sol-Gel method. Further modification by rare earth La was done through gaseous penetration route. Changes in constitution,structure,and electrical conductivity before and after modification of Ag and La were characterized. The acceptor dopant Ag owned the ability to decrease the resistivity of the doping samples from 4.30×109 Ω·m to 6.14×105 Ω·m where the resistivity fell by 4 orders of magnitude when the Ag doping ratio was 0.10%. And more doping of Ag enhanced the resistivity dramatically even beyond 2.0×107 Ω·m. Yet,gaseous penetration of La successively reduced the resistivity of BATO to the lowest point of 2.45×105 Ω·m. XRD analysis indicated that the doping process of Ag did not change the perovskite structure and main phases of the powders. However,new compound BaLa2O4 generated from complex reactions during the penetration process,which manifested that La3+ penetrated into the crystal lattices in the form of substituting the Ti4+ site. And this substitution strengthened the Ti-O bond,which led to the inhibition of blue shift in FTIR spectrum caused by doping of Ag. The morphology of La penetrated BATO powders detected by SEM and EDAX suggested that La did penetrate into the powders and this penetration process progressed the partly sintering of the powders which is in favor of the conductivity.The Ag-doped BaTiO3(BATO) polycrystalline powders were fabricated by Sol-Gel method. Further modification by rare earth La was done through gaseous penetration route. Changes in constitution,structure,and electrical conductivity before and after modification of Ag and La were characterized. The acceptor dopant Ag owned the ability to decrease the resistivity of the doping samples from 4.30×109 Ω·m to 6.14×105 Ω·m where the resistivity fell by 4 orders of magnitude when the Ag doping ratio was 0.10%. And more doping of Ag enhanced the resistivity dramatically even beyond 2.0×107 Ω·m. Yet,gaseous penetration of La successively reduced the resistivity of BATO to the lowest point of 2.45×105 Ω·m. XRD analysis indicated that the doping process of Ag did not change the perovskite structure and main phases of the powders. However,new compound BaLa2O4 generated from complex reactions during the penetration process,which manifested that La3+ penetrated into the crystal lattices in the form of substituting the Ti4+ site. And this substitution strengthened the Ti-O bond,which led to the inhibition of blue shift in FTIR spectrum caused by doping of Ag. The morphology of La penetrated BATO powders detected by SEM and EDAX suggested that La did penetrate into the powders and this penetration process progressed the partly sintering of the powders which is in favor of the conductivity.

关 键 词：gaseous penetration barium titanate rare earths electrical conductivity 

分 类 号：TB383.3[一般工业技术—材料科学与工程]